Matt (Miller) also mentioned somewhere that due to the TI's hull being more uniform throughout that the spacing could be a little more flexible. This it doesn't "have" to be 67 inches. However, it is still best to place the cradles under the scuppers or drive wells (as they are reinforced better to handle the hull weight). Hopefully this wonderfully vague post it helpful.

I don't have a trailer right now so I am sorry I cannot help you in measuring the trailer. But can you share with us what was the trailer that you are going to buy. Someone here might be familiar with that same trailer and will be able to help you.

67" is the recommended distance. My trailer is a little less than that. I have the Trailex Dbl/Dbl. Seems to work fine though. I might eventually get another set of cradles and add another bar or I might fabricate something for the bow to rest on.

When the TI cradles were designed there must have been an idea of where they shall support the hull. I have seen various recommendations in the forum but it would be nice to know the intention of Hobie. Does anyone know the "designed" distance from the bow (stem) to the foremost cradle?

Um.. while I don't mean to speak for Matt I believe he did mean TI... that or it doesn't matter as the principle is the same for the TI (meaning the cradles for both are designed to fit the hull at the front drive well and rear scuppers). I know on my TI after playing with the position of the cradles and watching the contact points closely that it seems to fit best when the forward cradle is just around the drive well and the rear cradle it just aft of the rear drive well close to the scuppers.

Actually I was referencing the AI as the original intended position for cradles and therefore the trailer crossbar spacing. Should have gone on to say that was how the 67" spacing came about. How you fit the TI cradles is variable, but would follow a similar concept of supporting at / near drive wells and scuppers. Also support out at the bow is important on the TI.

Now I am quite certain about how to fit the support beams for the cradles. There is only one piece of information I need as my beams on a converted Thule trailer will be fixed and not adjustable. Is the 67" measure from centre to centre of the cradles or is it an "in between" measure?

In order to be able to drive 80 km/h (50 m/h) I had to select a trailer approved by the Swedish road authority for such speed. Trailex are not available in Sweden.

I believe the 67" measurement was meant to be an 'in between' figure. However, as it's only a matter of inches in difference I don't think it will be too critical. When determining spacing I found it best to get under the kayak and watch the contact points closely to see where the cradles best match up with the hull (and this was under the drive well and rear scuppers in my case).